Réponse:
a. 3 ⁹/14
b. -3/10
c. 3 ³/70
Explications étape par étape:
a. 3/7 + 15/7 × 3/2
15×3=45
7×2=14
3/7 + 45/14
3×2=6
7×2=14
6/14 + 45/14= 51/14
51/14=3 ⁹/14
b. 9/5×(1/4 - 5/12)
(1/4 - 5/12)
1×3=3
4×3=13
(3/12 - 5/12)= -2/12
9/5 × -2/12= -18/60
-18/60= -3/10
c. (3/8 + 7/5) ÷ (9/4 - 5/2)
(3/8 + 7/5)
3×5=15
8×5=40
=15/40
7×8=56
5×8=40
56/40
(15/40+56/40)= 71/40
(9/4 - 5/3)
9×3=27
4×3=12
=27/12
5×4=20
3×4=12
=20/12
(27/12 - 20/12)= 7/12
71/40 ÷ 7/12= 71/40 × 12/7
= 213/70
= 3 ³/70
